CN1047576C - Alpha-alumina macrocrystals and making process therefor - Google Patents

Alpha-alumina macrocrystals and making process therefor Download PDF

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Publication number
CN1047576C
CN1047576C CN90107756A CN90107756A CN1047576C CN 1047576 C CN1047576 C CN 1047576C CN 90107756 A CN90107756 A CN 90107756A CN 90107756 A CN90107756 A CN 90107756A CN 1047576 C CN1047576 C CN 1047576C
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aluminum oxide
alumina
weight
hydrated aluminum
diameter
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CN1050366A (en
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安尼克·福尔
罗兰德·巴舍拉尔
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Arkema France SA
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Atochem SA
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/20—Aluminium oxides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B9/00—Single-crystal growth from melt solutions using molten solvents
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/20—Particle morphology extending in two dimensions, e.g. plate-like
    • C01P2004/22—Particle morphology extending in two dimensions, e.g. plate-like with a polygonal circumferential shape
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Paper (AREA)

Abstract

The aim of present invention is macrocrystals of alpha alumina in the form of monocrystalline hexagonal platelets. The invention also relates to a process for the manufacture of these macrocrystals by calcination of alumina, for example transition alumina, and in the presence of a fluorine-containing flux, at a relatively low temperature. The macrocrystals of alpha alumina can be employed as reinforcing materials.

Description

Big xln of the Alpha-alumina of wafer form and method for making thereof
The objective of the invention is to have the Alpha-alumina of sexangle wafer form or aluminum oxide or the big xln of corundum and by the set out method of the described xln of preparation of aluminum oxide or aluminium hydroxide.
Method by the big xln of preparation of aluminium hydroxide aluminum oxide has been described.Therefore, in French Patent 2441584, proposing some granularities is that 16-250 μ m and diameter/thickness ratio are the big xln of Alpha-alumina of the sexangle wafer form of 3/1-7/1, and these big xln are by obtaining in 1200-1450 ℃ of calcinations of aluminum hydroxide in the presence of the mineralizer of a kind of 0.001-0.5% of containing (weight) fluorine cpd.
In German patent application DE-OS2623482, propose at least a contain villiaumite and a kind of vanadic salts in the presence of, prepare the primary crystallization body that mean size is 16-25 μ m through the calcining of aluminium hydroxide.According to above-mentioned French Patent (page 2 19-22 is capable), heats up or use other mineralizer or hardly not influence the size and the crystalline form of xln fully.
In addition, Keiji DAIMON and Etsun KATO propose (1986 94 volumes of YogyoKvokai Shi the 3rd phase 380-382 page or leaf (78-80)) prepare the method for sexangle wafer that diameter is the Alpha-alumina of 1.5-40 μ m by hydrazine aluminum sulfate in the presence of aluminum trifluorides.
In Japanese patent application 60/54916, proposing mixture by hydrazine aluminum sulfate and the subcarbonate preparation mean diameter of setting out is that 1.7 μ m and thickness are the wafer of 0.18 μ m.
In Japanese patent application 60/38486, proposing preparation thickness is the wafer of 25-150 μ m (ratio by diameter/thickness sets out) less than 5 μ m and diameter.
In russian patent 416313, propose in 1170 ℃ a kind of aluminum compound thermal degradation to be prepared the sexangle wafer that diameter is the aluminum oxide of 4-12 μ m by in the presence of sexangle aluminum oxide nucleus.
At last, to propose in the presence of aluminum trifluoride by the alumina that the contains small amounts iron ratio for preparing diameter/thickness that sets out in 3 1981 years 197-198 pages or leaves of INTERCERAM NR be the alumina crystal body of 6-10 to B.P.Locsel.
The objective of the invention is to be basically the big xln of novel Alpha-alumina of monocrystalline sexangle wafer form, described wafer is characterised in that its diameter is 2-20 μ m, and thickness is 0.1-2 μ m, and the ratio of diameter/thickness is 5-40.
In these big xln, the present invention is 2-18 μ m about being diameter particularly, and thickness is 0.1-1 μ m, and the ratio of diameter/thickness is the big xln of Alpha-alumina of the sexangle product sheet form of 5-40.
Purpose of the present invention also is the method that a kind of preparation is the Alpha-alumina of aforesaid sexangle wafer form basically, the method is characterized in that a kind of fusing point the most high in 800 ℃, contain the fluorine that chemistry connects and be under the flux of solvent exists, to carry out the calcining of transitional alumina or hydrated aluminum oxide under the molten state of transitional alumina or hydrated aluminum oxide.
" transitional alumina or hydrated aluminum oxide " is used to represent that this method is applicable to the aluminum oxide or the aluminium hydroxide of form of ownership except that Alpha-alumina.
Flux, be referred to as mineralizer equally, meet above-mentioned feature, basically be fluorine cpd by one or more non-hydrolysables, (one or more) fluorine cpd that perhaps comprise described non-hydrolysable are formed with hydrolyzable fluorine cpd a kind of pair of compound mutually mutually, and described one is dissolved in the another one phase mutually.
For above-mentioned flux is described, will mention two compounds of the fluorochemical that contains aluminum trifluoride and one or more basic metal or alkaline-earth metal fluoride, particularly lithium, sodium, potassium or calcium especially.Also will propose to be Li especially 3AlF 6The AlF of (sodium aluminum fluoride) form 3Two compounds of-LiF or also have Li 3Na 3(AlF 6) 2(cryolithionite) or 3AlF 35LiF (chiolite).
The flux that uses among the present invention is powder type, and its granularity is preferably less than 1mm (particle of at least 50% (weight)).
In enforcement, for transitional alumina that uses and hydrated aluminum oxide, use 2% at least, preferably the flux of 4-20% (weight) according to the inventive method.
Transitional alumina or hydrated aluminum oxide can be selected from the powder-product of large-scale various diameter and specific surface area.The special particle diameter that proposes at least 50% (weight) better is lower than 25 μ m less than 50 μ m, is lower than the aluminum oxide of 1.5 μ m especially.In these aluminum oxide, preferred specific surface area＞100m 2/ g (recording by the BET method) is preferably 100-400m 2The aluminum oxide of/g.
Though can use the exsiccant aluminum oxide, preferred water content reaches the aluminum oxide (Al of undried or hydration of 15% (weight) of alumina weight 2O 3H 2O).
Calcining temperature can reach 1200 ℃, even higher.Yet this has constituted the advantage according to method of the present invention especially, and calcining can be carried out under 900-1100 ℃ under low temperature very.
According to usual method, the transition or the hydrated aluminum oxide/flux mixture that are made by general powder mixes technology can place heating container at ambient temperature, heat up until preset value gradually.Preferably be rapidly heated, promptly per hour 1000 ℃, this saying under any circumstance all should not limit the scope of this invention.
Calcining is preferably in the lazy angry atmosphere, for example carries out in thin nitrogen gas stream.In case reach calcining temperature, as previously mentioned, temperature can more properly be about 1000 ℃, preferably with this temperature maintenance certain hour (-several hours half an hour is for example until 5 hours) at 900-1100 ℃.
After calcination operation finishes, can indistinction ground carry out the quenching of wafer or with its naturally cooling or in refrigerator, cool off.
The wafer of collecting [＞90% (weight)] basically is by the Alpha-alumina such as the Al that may combine with the derivative of flux or flux 4LiO 6F is (at Li 3AlF 6Situation under) flux that constitutes or its derivative can be for example by (according to appointment about 100 ℃) concentrated acid (H of a kind of heat 2SO 4Or HCl) effect is removed.
Purpose of the present invention, the sexangle wafer of Alpha-alumina is applicable to multiple use.They especially can be used for producing the polishing product, can make the enhancing substance of various materials, particularly ceramic base and metal and polymeric matrix equally, are used in combination separately or with fiber, particle, whisker.
Following example explanation the present invention.
Example 1-14
The equipment that uses comprises the silica tube process furnace, can lead to nitrogen gas stream therein, and sends into therein the agglomerating alumina crucible of wanting the incinerating powder is housed.
With following aluminum oxide (DX=Y μ m represents that its diameter of particle of X% (weight) is less than Y μ m):
·P 1:γ-Al 2O 3D 50=1,1μm
Specific surface area=172m 2/ g
·P 2:γ-Al 2O 3D 50=4,6μm
Specific surface area=100m 2/ gP 3: Al 2O 3H 2O (boehmite) D 60=25 μ mD 96=45 μ m
Specific surface area=196m 2/ g
·P 4:γ-Al 2O 3 D 55=25μmD97=45μm
Specific surface area=244m 2/ g
·P 5:γ-Al 2O 3 D 50=3,5μm
According to respect to aluminum oxide (P 1To P 5) weight be that 5% (weight) is used following flux (D 50=μ m as defined above, D is equivalent to whole particles): F 1: Li 3AlF 6(Pf:776 ℃) D 50=0,9 μ mF 2: Li 3AlF 6400＜D＜600 μ mF 3: Li 3AlF 6D＞630 μ mF 4: Li 3AlF 6160＜D＜400 μ mF 5: Li 3Na 3(AlF 6) 2(Pf:710 ℃) F 6: 3AlF3,5LiF
Aluminum oxide and flux mix at ambient temperature, put into crucible then, and (10l/ hour) sent into crucible in the stove under nitrogen gas stream.
(rising part) rises to X ℃ with furnace temperature in 1 hour, then this temperature kept Z hour (horizontal component).
Under environmental gas, cool off.
The product that obtains is a white blocks, is easy to the demoulding and scatters.Measure the mean diameter d (in μ m) and the average thickness e (in μ m) of the wafer that forms.
Condition and result all are collected in the following table:
Example Aluminum oxide Flux Calcine X ℃ of level partly (z) Wafer size d e
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 P 1 P 2 P 3 P 4 P 5 P 1 P 1 P 1 P 2 P 1 P 1 P 1 P 1 P 1 P 1 F 1 F 1 F 1 F 1 F 1 F 2 F 3 F 4 F 4 F 1 F 1 F 1 F 1 F 5 F 6 980 980 980 980 980 980 980 980 980 980 980 850 1100 980 980 1 1 1 1 1 1 1 1 1 1/2 2 1 1 1 1 7 16 16 8 4 5 5 10 9 7 7 7 7 8 7 0,5 0,5 1 1 0,3 0,7 0,7 0,5 1 0,5 0,5 0,5 0,5 0,5 0,5

Claims (19)

1. the method that is the big xln of Alpha-alumina of monocrystalline hexagonal disks crystalline form by transitional alumina or hydrated aluminum oxide and the preparation of a kind of fusing assistant basically, wherein to have diameter be 2 to 20 μ m to this platelet, thickness is that 0.1-2 μ m and diameter/thickness ratio are 5 to 40, the method is characterized in that and use its fusing point to be up to 800 ℃ and contain the fluorine of chemical bonding and can under molten state, dissolve the fusing assistant of transitional alumina or hydrated aluminum oxide, and in the presence of this fusing assistant, transitional alumina or hydrated aluminum oxide are calcined at 900-1200 ℃.
2. according to the process of claim 1 wherein that the prepared macrocrystalline platelet of Alpha-alumina that is monocrystalline hexagonal disks crystalline form basically is that to have diameter be that 2 to 10 μ m and thickness are the macrocrystalline platelet of Alpha-alumina of 0.1 to 1 μ m.
3. according to the method for claim 1, it is characterized in that this fusing assistant mainly contains the fluorochemical of one or more non-hydrolysables or contains a kind of system, this system contains phase comprising said one or more fluorochemicals and comprises second of a kind of hydrolyzable fluorochemical mutually, and, a wherein said phased soln another mutually in.
4. according to the method for claim 3, it is characterized in that this fusing assistant comprises a kind of system, this system is by being aluminum trifluoride on the one hand and being formed by one or more alkaline metal fluoride cpds or alkaline-earth metal fluoride on the other hand.
5. according to the method for claim 4, it is characterized in that this alkaline metal fluoride cpd or alkaline-earth metal fluoride are by selecting in lithium fluoride, Sodium Fluoride, Potassium monofluoride and the Calcium Fluoride (Fluorspan).
6. according to the described method of any one claim of claim 3 to 5, it is characterized in that this fusing assistant comprises with Li 3AlF 3The AlF of (cryolithionite) form 3-LiF, Li 3Na 3(AlF 6) 2(cryolithionite) or 3AlF 35LiF (lithium chiolite).
7. according to the method for any one claim in the claim 3 to 5, it is characterized in that using the amount of fusing assistant with respect to for the weight of incinerating transitional alumina or hydrated aluminum oxide, being at least 2%.
8. according to the method for claim 7, wherein the amount of employed flux is with respect to be 4-20% for the weight of incinerating transitional alumina or hydrated aluminum oxide.
9. according to the method for claim 6, the amount that it is characterized in that the flux that uses is with respect to be at least 2% for the weight of incinerating transitional alumina or hydrated aluminum oxide.
10. according to the method for claim 9, wherein the amount of employed this flux is with respect to be 4-20% for the weight of incinerating transitional alumina or hydrated aluminum oxide.
11. method according to any one claim in the claim 3 to 5, it is characterized in that transitional alumina or hydrated aluminum oxide comprise a kind of powder, wherein its diameter of the particle of at least 50% (weight) is less than 50 μ m, and the specific surface area that described aluminum oxide has is greater than 100m 2/ g.
12. according to the method for claim 6, it is characterized in that transitional alumina or hydrated aluminum oxide comprise a kind of powder, wherein its diameter of the particle of at least 50% (weight) is less than 50 μ m, the specific surface area that described aluminum oxide has is greater than 100m 2/ g.
13. according to the method for claim 7, it is characterized in that transitional alumina or hydrated aluminum oxide comprise a kind of powder, wherein its diameter of the particle of at least 50% (weight) is less than 50 μ m, the specific surface area that described aluminum oxide has is greater than 100m 2/ g.
14., it is characterized in that aluminum oxide contains the water that is up to 15% (weight) according to the method for claim 7.
15., it is characterized in that calcining temperature is 900-1100 ℃ according to the method for any one claim in the claim 3 to 5.
16., it is characterized in that calcining temperature is 900-1100 ℃ according to the method for claim 6.
17., it is characterized in that calcining temperature is 900-1100 ℃ according to the method for claim 7.
18., it is characterized in that calcining temperature is 900-1100 ℃ according to the method for claim 11.
19., it is characterized in that calcining temperature is 900-1100 ℃ according to the method for claim 13.
CN90107756A 1989-09-21 1990-09-21 Alpha-alumina macrocrystals and making process therefor Expired - Fee Related CN1047576C (en)

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FR8912402A FR2652075B1 (en) 1989-09-21 1989-09-21 ALPHA ALUMINA MACROCRYSTALS IN THE FORM OF PLATES AND PROCESS FOR OBTAINING SAME.
FR8912402 1989-09-21

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CN108560052B (en) * 2018-04-26 2020-05-01 闽江学院 Preparation method and application of monocrystal hexagonal alumina
CN113329972B (en) * 2019-01-25 2022-09-20 Dic株式会社 Plate-like alumina particles and method for producing plate-like alumina particles
JP6708281B2 (en) * 2019-03-27 2020-06-10 Dic株式会社 Plate-shaped alumina particles
JP7524945B2 (en) 2019-10-09 2024-07-30 Dic株式会社 Plate-like alumina particles and method for producing plate-like alumina particles
WO2021068125A1 (en) * 2019-10-09 2021-04-15 Dic Corporation Plate-like alumina particle and method for manufacturing plate-like alumina particle
CN110938862A (en) * 2019-12-23 2020-03-31 苏州纳迪微电子有限公司 High-purity monocrystalline corundum powder and preparation method thereof
CN114057505B (en) * 2021-12-13 2023-02-28 西安邮电大学 Preparation method of porous flaky alumina framework

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EP0425325B1 (en) 1993-12-08
KR950003419B1 (en) 1995-04-12
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FR2652075B1 (en) 1991-12-06
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DD295885A5 (en) 1991-11-14
ATE98304T1 (en) 1993-12-15
FR2652075A1 (en) 1991-03-22

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